Armature-winding for electrical machines.



PATENTED MAY 26-, 1908.

B. G. LAM M E ARMATUBE WINDING Pea ELECTRICAL MACHINES.

APPLIA'TIon FILED AUG. 17.1904.

' INVENTOR JINESSES:

ATTORNEY netic circuit.

UNITED STA 'I ES PATENT OFFICE.

BENJAMIN G. LAMME, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELEC- ARMATURE-WINDIN G FOR ELECTRICAL MACHINES.

Specification of Letters Patent.

Patented May 26, 1908.

Application filed. August 17 190%. Serial No. 221,093-

Toall whom it may concern:

Be it known that I, BENJAMIN G. LAMME, a citizen of the United States, and a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Armature-Windings for Electrical Machines, of which the following is a specification.

My invention relates to armature windings for electrical machines, and it has for its object to provide a winding for machines having small numbers of poles and large diameters which will aiiord a better mechanical construction than any heretofore devised for the purpose and by the use of which a characteristic curve of practically a sine Wave form may still be obtained.

It frequently occurs in the design and construction of electrical machines that two poles correspondin to each current phase are employed, whici heretofore has required a winding having spans of 180, resulting in a rather weak mechanical construction. In

. the winding comprising my present inventlon, the length of the end connectors is very much reduced as compared with the ordinary constructionand, consequently, a better and more satisfactory mechanical construction is afforded, while the sine wave form of the characteristic curve remains substantially tions of the magnetic circuit and south poles in the corresponding opposite portions, I have provided the armature with a winding in two parts for each phase, one portion of each. of the windings inducing, at any instant, north poles in certain portions of the .magnetic circuit and the other portions inducing south poles, at the same instant, in corresponding 0 osite'portions of the magl iith thls arrangement, if a machine is'designed for ope ation on threephase circuits, the polar spanfor each portion of the winding is one-third of the circumference of the armature, or the maximum span for any one coil is 120, and in a two-phase machine, the polar span for each portion 'of the winding is one quarter of the circumference of the armature, or the maximum span for any one coil is 90.

In t of a two-pole machine is divided into two portions 0. and a, the ortion a being wound so that it spans one-t ird of the circumfer ence, or from slots 1 to 12, and occupies alternate slots between these numbers, the portion a spanning one-third of the lei-r cumference from slot 19 to slot 30 and 0c' e drawing, the Winding for phase cupying-alternate slots between those num hers. nected that at the same instant the former produces a north 'pole at N and the latter a south pole at S. The other two phases of: the winding are similarly wound and occupy the remaining vac ant slots, the windings being connected together at their inner ends in order to form a complete star winding for the armature. With this arrangement of windings, the voltage generated with a given numberof wires in each slot is practically one-half that of the ordinary type of Winding; that is, in order that the same voltage may be generated by a machine constructed in accordance with this invention as would be generated by a machine of the ordinary construction, the number of conductors in each slot must be doubled. However, this is not a serious disadvantage, for the reason that the amount of available space in the slots for the winding is ample and the increased number of turns is therefore permissible.

' While I have shown and described my invention as applied only to a three-phase machine, it is evident that a similar construction of winding may be provided for two-phase machines. It is also evident that the use of coils for each phase of current that induce corresponding op osite magnetic poles a.

The two portions a and a are so 0011- this type of winding is not limited totwoproximately e ectrical degrees. apart, t e

sides of the coils of each group alternating in corresponding to different 'al-ternate in position.

phase of current that position with the sides offthose of other groups that correspond to the other phase or phases of current.

'2. In a polyphase electrical machine, a

slotted armature and a winding for" each phase of current that comprises as many groups of a plurality of coils each as there are eld poles, the coils of each group being located in slots that alternate in position with those which contain the coils of other groups that correspond to the other phase or phases ofcurrent.

3. In a polyphase electrical machine; a slotted armature and a winding for each groups of a plurality of co each as there are field poles, the windings being distributed in the armature slots so that the sides of coils phases of current 4. A winding for polyphase electrical ma chines comprising a plurality of coils that are COI1111pI'lS8S as many coiis'equal in number to the roduct of the 6. A Winding for polyphase electrical ma-- 'chines comprising a plurality of groups of coils equal in number to the product of the number" of field poles by the number of phases, the sides of the'coils of each group alternating in position with the sides of the i coils of other groups, and each phase position of the winding being arranged to produce opposite magnetic poles 180 electrical degreesapart.

7. A winding for polyphase electrical machines, each phase circuit of which comprises as many groups of a plurality of coils each as there are field poles, the sides of the coils of each group alternating in position with the sides of the coils of other groups.

In testimony whereof, I have hereunto subscribed my name this 1 1th day of August, 1904. i

BENJ. G. LAMME Witnesses:

E. M. STEWART, BIRNEY HINEs. 

